Equivalents For Carbon Dioxide Research Articles

Effect of Off-Season Iron Supplementation on Aerobic Capacity of Female Handball Player: A Randomized, Double-Blinded, Placebo-Controlled Study

BackgroundIron supplementation, especially in female athletes, is 1 of the influential factors in aerobic capacity, and its deficiency can lead to significant problems related to reduced aerobic capacity. ObjectivesThis study aimed to investigate the effect of 3 wk of iron supplementation on the aerobic capacity of female handball players. MethodsIn this randomized, double-blinded, and placebo control trial, 14 elite handball players (age: 21.6 ± 5.68 y; height: 169.5 ± 4.9 cm; weight: 62.2 ± 9.25 kg; body mass index (in kg/m2): 21.5 ± 2.9) randomly divided into 2 supplement groups (receiving a 100 mg/d of poly-maltose tri hydroxide iron complex in the form of tablets) and the placebo group (receiving a tablet containing 100 mg/d starch which is the same color and shape as iron tablets). The supplementation protocol was performed for 3 wk during the off-season. Maximal oxygen consumption (VO2max), amounts of carbon dioxide at the first ventilatory threshold, amounts of carbon dioxide at the second ventilatory threshold, time to exhaustion (TTE), pulmonary ventilation (VE), ventilatory equivalents for oxygen, amounts of oxygen at the first ventilatory threshold, amounts of oxygen at the second ventilatory threshold, time to reach first ventilatory threshold, end-tidal partial pressure of oxygen at the first ventilatory threshold, end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and ventilatory equivalents for carbon dioxide were measured using the Bruce test and gas analyzer in 2 pretest and posttest stages. ResultsThere were significant improvements in oxygen at the first ventilatory threshold, time to reach first ventilatory threshold, and end-tidal partial pressure of carbon dioxide at the first ventilatory threshold and a significant decrease in end-tidal partial pressure of oxygen at the first ventilatory threshold (P < 0.05). Also, no significant changes were found in VO2max, carbon dioxide at the first ventilatory threshold, carbon dioxide at the second ventilatory threshold, oxygen at the second ventilatory threshold, TTE, VE, ventilatory equivalents for oxygen, and ventilatory equivalents for carbon dioxide after 3 wk of iron supplementation (P > 0.05). ConclusionsThe study found that 3 wk of off-season iron supplementation positively impacted female handball players’ aerobic capacity; however, it did not significantly improve their VO2max.

The oral contraceptive cycle and its influences on maximal and submaximal endurance parameters in elite handball players.

The usage of the oral contraceptive pill is widespread among athletes of various levels. However, there is limited knowledge on how the intake of the pill alters the submaximal and maximal endurance parameters between the oral contraceptive phases. Therefore, the aim of this study was to examine potential differences between the pill intake and withdrawal phase on endurance-related parameters in first-division handball players. In total, 15 female team handball players performed two graded exercise tests until volitional exhaustion on a motorized treadmill. Tests were performed during the pill intake (days 16-17) and withdrawal phase (day 2-3). Throughout the test, respiratory gases were measured breath-by-breath, and the heart rate was measured continuously. Before and after the graded exercise test, blood samples were obtained in order to assess the blood lactate concentration. Before each test, venous blood samples were taken to determine endogenous sex hormone levels. Ventilatory parameters (O2, CO2, and E, and respiratory equivalents for O2 and CO2) were measured, and the oxidation of fat and carbohydrates was calculated. A paired-sample t-test was used to assess differences between the two time points, and the significance was accepted as p < 0.050. Significant differences with lower values during the consumption phase were found for absolute (mean difference ± SD: 88 ± 131mL∙min-1; p = 0.021) and relative O2peak (mean difference ± SD: 1 ± 2mL∙min-1∙kg-1; p = 0.012). Higher values during the consumption phase were found for submaximal respiratory equivalents for O2 (mean difference ± SD: -1.1 ± 1.7; p = 0.028) and CO2 (mean difference ± SD: -0.9 ± 1.5; p = 0.032). No differences were found for all other parameters, including differences for endogenous sex hormones (p > 0.050). The results of the current study suggest only marginal and physiologically insignificant differences in endurance-related parameters between oral contraceptive phases.

Soil Carbon: Pool, Loss, Emission and Climate Change Sources and Knowledge Level of Some Land Use Systems in Sudan Savanna, Kwara State

This research work was carried out in Sudan savanna of Kwara State to determine the effects of land use types on soil carbon pool, loss, emission and to determine the farmer’s knowledge level and sources of information on climate change. Six villages were selected randomly and in each Local Government Area, three villages were visited and three farms planted each with maize/cassava intercrop, cashew plantation and natural forest were sampled. Soil samples were collected from the farmland randomly at the depth of 0–20cm and analysed for physical and chemical properties in the laboratory. Carbon pool index was higher under cashew plantation. The mass of carbon lost recorded was higher under maize/cassava intercrop and cashew plantation recorded the lowest mass of carbon lost. Equivalent Carbon dioxide emitted recorded was lower under cashew plantation and maize/cassava intercrop recorded higher equivalent of carbon dioxide emitted. Natural forest had the highest organic carbon. Simple random sampling of 126 respondents were interviewed. Results revealed majority (71.4%) are willing to invest in residue retention and 92.9% are willing to engage in climate change mitigation practices free of charge. Maize/cassava intercrop recorded the lowest carbon pool due to burning of plant residues and the use of tillage practices. The highest carbon pool index recorded under cashew plantation was due to leaves litter decomposition. Carbon emitted was generally higher under maize/cassava intercrop as a result of continuous and vigorous cultivation leading to loss of carbon. Some farmers are not fully aware of climate change mitigation practices, therefore, more observation should be given to afforestation scheme to mitigate climate change and government and nongovernmental organization (NGOs) should educate and encourage farmers to practice crop residue retention and also minimize bush burning.

Preoperative aerobic fitness and perioperative outcomes in patients undergoing cystectomy before and after implementation of a national lockdown

BackgroundLower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy. MethodsWe reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared. ResultsWe identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9–10.9] vs 10.3 [9.1–12.3] ml kg−1 min−1; P=0.0002), peak oxygen uptake (15.5 [12.9–19.1] vs 17.5 [14.4–21.0] ml kg−1 min−1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4–38.5] vs 33.4 [30.5–36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143–6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368–6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427–7.960; P=0.004), compared with pre-lockdown on univariate analysis. ConclusionsLockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy.

Reactivity of NHI-Stabilized Heavier Tetrylenes towards CO2 and N2 O.

A heteroleptic amino(imino)stannylene (TMS2 N)(It BuN)Sn: (TMS=trimethylsilyl, It Bu=C[(N-t Bu)CH]2 ) as well as two homoleptic NHI-stabilized tetrylenes, (It BuN)2 E: (NHI=N-heterocyclic imine, E=Ge, Sn) are presented. VT-NMR investigations of (It BuN)2 Sn: (2) reveal an equilibrium between the monomeric stannylene at room temperature and the dimeric form at -80 °C as well as in the solid state. Upon reaction of the homoleptic tetrylenes with CO2 , both compounds insert two equivalents of CO2 , however differing bonding modes can be observed. (It BuN)2 Sn: (2) inserts one equivalent of CO2 into each Sn-N bond, giving carbamato groups coordinated κ2 O,O' to the metal center. With (It BuN)2 Ge: (3), the Ge-N bonds stay intact upon activation, being bridged by one molecule of CO2 respectively, forming 4-membered rings. Furthermore, the reactivity of 2 towards N2 O was investigated, resulting in partial oxidation to form stannylene dimer [((It BuN)3 SnO)(It BuN)Sn:]2 (6).

CO2-Sensitive Porous Magnet: Antiferromagnet Creation from a Paramagnetic Charge-Transfer Layered Metal-Organic Framework.

Porous magnets that undergo a magnetic phase transition in response to gaseous adsorbates are desirable for the development of sustainable sensing and memory devices. Familiar gases such as O2 and CO2 are one class of target adsorbates because of their close association with life sciences and environmental issues; however, it is not easy to develop magnetic devices that respond to these ubiquitous gases. To date, only three examples of gas-responsive magnetic phase transitions have been demonstrated: (i) from a ferrimagnet to an antiferromagnet, (ii) its vice versa (i.e., change of magnetic phase), and (iii) from a ferrimagnet to a paramagnet (i.e., erasure of the magnetic phase). However, the creation of a magnet, meaning the change from a nonmagnet to a magnet by O2 or CO2 gas adsorption and magnetic switching by this phenomenon have not yet been explored. Herein, we report a CO2-induced antiferromagnet modified from a paramagnetic charge-flexible layered compound, [{Ru2(2,4-F2PhCO2)4}2TCNQ(OEt)2] (1; 2,4-F2PhCO2- = 2,4-difluorobenzoate; TCNQ(OEt)2 = 2,5-diethoxy-7,7,8,8-tetracyanoquinodimethane), where three molar equivalents of CO2 was accommodated at a CO2 pressure of 100 kPa. The magnetic change originates from charge fluctuation due to the transfer of electrons moving from the electron-donor to the electron-acceptor unit or vice versa, resulting in a change in the electron distribution induced by CO2 adsorption/desorption in the donor-acceptor-type charge transfer framework. Owing to the reversible electronic state change upon CO2 adsorption/desorption, these magnetic phases are switched, accompanied by modification of the electrical conductivity, which is boosted by the CO2 accommodation. This is the first example of the creation of a CO2-responsive magnet, which is promising for novel molecular multifunctional devices.

The effectiveness of high-intensity interval training compared to moderate-intensity continuous training in patients with heart failure: a systematic review and meta-analysis

Abstract Background/Introduction Cardiac rehabilitation including exercise therapy is beneficial for improving exercise tolerance, physical function, quality of life (QOL), and life expectancy in patients with heart failure. High-intensity interval training (HIIT) has attracted attention as a new training modality in heart failure, whereas moderate-intensity continuous aerobic training (MCT) is recommended as the main training modality to improve exercise tolerance. However, the effects of HIIT in patients with heart failure remain controversial. Purpose This systematic review and meta-analysis aimed to examine the effectiveness of HIIT compared to MCT on exercise tolerance in patients with heart failure. Methods We searched for studies published up to 4 March 2022 in EMBASE, MEDLINE via Ovid SP, PubMed, and the Cochrane Library via Wiley Online Library with no limitations on data, language, or publication status. We included randomised controlled trials comparing the effectiveness of HIIT and MCT on peak oxygen uptake (VO2), as a measure of exercise tolerance, aerobic threshold (AT) VO2, ventilatory equivalent of carbon dioxide (VE/VCO2), and QOL. We pooled the data on peak VO2, compared HIIT to MCT, and conducted a sub-analysis if there was heterogeneity in the result. Results We identified 15 randomised controlled trials with 557 patients from a total of 23,272 records. Our meta-analysis showed that participants who underwent HIIT achieved a significantly higher peak VO2 than those who underwent MCT (mean difference 1.46 ml/kg/min, 95% confidence interval 0.39 to 2.53; I2 = 65.7%; very low-quality evidence) (Figure 1). Participants who underwent HIIT had no statistically significant difference in AT VO2, VE/VCO2, and QOL compared to those who underwent MCT. The meta-regression analysis, conducted as a sub-analysis to explore possible causes of heterogeneity, revealed that the effect size of HIIT compared to MCT was inversely associated with body mass index (r = -0.508, p = 0.028, 95% confidence interval -0.95 to -0.07) (Figure 2). Conclusions Our systematic review showed that HIIT achieved a higher peak VO2 than MCT in patients with heart failure. In addition, HIIT may be more effective in improving exercise tolerance in patients with low body mass index.

Abstract 15275: Cardiac Magnetic Resonance Ventricular Function and Hemodynamic Multivariable Model Predictors of Exercise Performance in Tetralogy of Fallot Using Machine Learning and Multivariable Modelling: A Substudy of the Single Center Cardiac Magnetic Resonance Outcomes Registry-Tetralogy of Fallot

Background: There are no robust predictors of exercise performance in repaired tetralogy of Fallot (rTOF) using both ventricular function and hemodynamics. Aim: To utilize machine learning and multivariable modeling to determine cardiac magnetic resonance (CMR) and other metrics predictive of exercise performance. Methods: We retrospectively reviewed data of all rTOF pts undergoing CMR from 2005-2020. Those who had cardiopulmonary exercising testing (CPET) within 6 months of CMR were analyzed using the machine learning technique LASSO to choose candidate variables for subsequent testing with multivariable modeling. CMR parameters included right (RV) and left ventricular (LV) function and hemodynamics. Significance P&lt;0.05. Results: 266 of 761 pts with rTOF met the inclusion criteria (age at CMR 16.1 + 9.7 years old, age at repair 0.36 years old, 56% male). Higher RV mass, RV global function index and lower pulmonary regurgitant fraction (PR) were independently associated with higher % predicted (%P) maximum oxygen consumption (VO 2 max). In addition, females and non-syndromic pts were also associated with higher %P VO 2 max (table). Those with a higher LV end-diastolic volume (EDV), females and pts without pulmonary atresia performed better at %P work. Those with a higher RV mass/volume demonstrated a worse ventilatory equivalent of carbon dioxide (VE/VCO 2 ). See table. Conclusion: RV ventricular functional parameters, PR (hemodynamics), gender and syndromic status are all independently associated with %P VO 2 max. Those with larger LV volumes were able to perform more work and those with a higher RV mass/volume had a worse VE/VCO 2 . Our findings shed some light into the etiology of poor rTOF exercise performance.

Cardiorespiratory Reactions During Submaximal Exercise in Humans after 14-Day Simulated Lunar Gravity

The paper presents main results of a study on the influence of the physiological effects of simulated lunar gravity on cardiorespiratory responses to exercise in humans. Twelve healthy male volunteers aged 19–31 years (M ± SD: 22.5 ± 4.0 years) took part in the study. They were under 14-day head-up bed rest at +9.6° angle (HUBR) relative to the horizon as a model for the physiological effects of lunar gravity. Cardiopulmonary exercise testing (CPET) was performed 7 days before the onset of HUBR and on the next day after the end of the experimental exposure. A 3-stage cycle ergometer test with 5-minute platforms at 125, 150, and 175 watts was used as a CPET protocol. Exposure of subjects to simulated lunar gravity reduced their tolerance to physical load. This was indicated by more pronounced changes for such parameters of cardiorespiratory system as heart rate, minute ventilation of the lungs, ventilatory equivalents for oxygen and carbon dioxide, as well as a less pronounced increase in oxygen consumption and oxygen pulse during CPET after 14 days of exposure to HUBR.

Long-term effects of physical training on cardiopulmonary exercise parameters in young patients with congenital heart diseases.

Physical activity is recognised as an important intervention in patients with CHD. However, more data on the actual magnitude of physical training impact on functional capacity in this group of patients are still warranted. We aim to assess effort tolerance in a contemporary cohort of patients with congenital heart disease, regularly following a training programme, in comparison with a matched control group. Patients with CHD followed at the sports medicine department, who had undergone cardiopulmonary exercise test between 2011 and 2019, were included. Variables recorded were maximum workload, absolute and indexed maximum oxygen consumption, maximum heart rate, absolute and indexed maximum O2 pulse, ventilatory equivalent of CO2 and oxygen consumption/Work. Trend of cardiopulmonary parameters was analysed over time. Maximal workload, maximum oxygen consumption and ventilatory equivalent of CO2 were compared with a control group of patients with a more sedentary lifestyle, matched for diagnosis, gender, age, and body mass index. Among one hundred and eleven patients, 73 males (66%) were analysed. Median age was 14 (12-17) years. Twenty-nine patients (27%) were practising sports at competitive level. Maximum oxygen consumption and oxygen consumption % of maximum predicted were not significantly different at follow-up as compared with baseline. Follow-up of maximum oxygen consumption was 38.2 ± 9 ml/kg/min versus 38.6 ± 9.2 ml/kg/min (p = NS) and follow-up of %oxygen consumption was 88 ± 20 versus 87 ± 15 (p = NS). Ventilatory equivalent of CO2 significantly improved in the last test as compared with the baseline: 30 ± 4 versus 33 ± 5 (p = 0.002). As compared with the control group, trained patients displayed a significantly higher maximum workload and oxygen consumption, while ventilatory equivalent of CO2 was not significantly different. In our cohort, patients following a regular training programme displayed a significantly higher functional capacity as compared with not trained control group, irrespective of NYHA class. Objective functional capacity was stable over a median follow-up of 3 years.

Analysis of Greenhouse Gas Emissions Characteristics and Emissions Reduction Measures of Animal Husbandry in Inner Mongolia

Global warming has had a profound impact on human life, with animal husbandry being a significant contributor to greenhouse gas emissions and playing a crucial role in the global greenhouse gas budget. Inner Mongolia is a major contributor to these emissions, making it vital to study the link between greenhouse gas emissions and animal husbandry in this region for the purpose of reducing emissions. In this study, the emissions of greenhouse gases (CH4, N2O, and CO2) from livestock and poultry breeding from 2010 to 2020 and the emissions of each city from 2020 were estimated, the emissions characteristics were analysed, and the low carbon emissions reduction technical measures were proposed. The results show that (1) the overall greenhouse gas emissions from 2010 to 2020 in Inner Mongolia showed a fluctuating trend; the main emissions sources were gastrointestinal fermentation and faecal management. The annual average CH4 emissions were 994,400 ta−1, and the annual average N2O emissions were 35,100 ta−1. (2) In 2020, the total emissions of each league city were 38.05 million t equivalent of CO2, and the emissions gradually decreased from east to west, with a significant emissions reduction potential. Based on these findings, this study also proposed technical measures for reducing carbon emissions, offering theoretical support to drive the industrial transformation and upgrading of the livestock industry, and promoting green economic development in Inner Mongolia as part of its carbon peaking and neutrality goals.

Cardiovascular capacity in adults with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) patients have a decreased exercise capacity. Potential cardiovascular capacity in patients with OSA with different severity without known cardiovascular disease has not been described.OBJECTIVE: To evaluate impaired potential exercise cardiovascular capacity during cardiopulmonary exercise testing (CPET) in OSA patients and to compare cardiovascular performance reaction with different severity during graded exercise stages.DESIGN: All participants were accompanied without cardiovascular disease, especially hypertension and arrhythmia. Parameters of different stages were compared between subjects with and without OSA, and among OSA patients with varied severity.RESULTS: Despite having significantly higher peak exercise diastolic blood pressure (DBP) and ventilatory equivalent for CO2 (EQCO₂), patients with OSA had a lower peak oxygen uptake (VO₂), heart rate (HR), heart rate recovery (HRR) and respiratory reserve (BR) than normal subjects. Furthermore, significant correlations were found between VO₂, DBP, EQCO₂, HRR, BR and the apnoea-hypopnea index. In severe OSA, there was a greater difference in HR and HRR during the anaerobic threshold stages.CONCLUSIONS: OSA patients demonstrate reduced potential cardiovascular capacity, even without documented cardiovascular disease. Patients with severe OSA develop impaired exercise capacity at early stage during exercise. These data point to exaggerated haemodynamic response to graded exercise and delayed post-exercise cardiovascular response recovery in OSA patients. CPET can be a supplement for assessment of OSA severity.

An Aluminium Imide as a Transfer Agent for the [NR]2- Function via Metathesis Chemistry.

The reactions of a terminal aluminium imide with a range of oxygen-containing substrates have been probed with a view to developing its use as a novel main group transfer agent for the [NR]2- fragment. We demonstrate transfer of the imide moiety to [N2 ], [CO] and [Ph(H)C] units driven thermodynamically by Al-O bond formation. N2 O reacts rapidly to generate the organoazide DippN3 (Dipp=2,6-i Pr2 C6 H3 ), while CO2 (under dilute reaction conditions) yields the corresponding isocyanate, DippNCO. Mechanistic studies, using both experimental and quantum chemical techniques, identify a carbamate complex K2 [(NON)Al-{κ2 -(N,O)-N(Dipp)CO2 }]2 (formed via [2+2] cycloaddition) as an intermediate in the formation of DippNCO, and also in an alternative reaction leading to the generation of the amino-dicarboxylate complex K2 [(NON)Al{κ2 -(O,O')-(O2 C)2 N-(Dipp)}] (via the take-up of a second equivalent of CO2 ). In the case of benzaldehyde, a similar [2+2] cycloaddition process generates the metallacyclic hemi-aminal complex, Kn [(NON)Al{κ2 -(N,O)-(N(Dipp)C(Ph)(H)O}]n . Extrusion of the imine, PhC(H)NDipp, via cyclo-reversion is disfavoured thermally, due to the high energy of the putative aluminium oxide co-product, K2 [(NON)Al(O)]2 . However, addition of CO2 allows the imine to be released, driven by the formation of the thermodynamically more stable aluminium carbonate co-product, K2 [(NON)Al(κ2 -(O,O')-CO3 )]2 .

An Aluminum Telluride with a Terminal Al=Te Bond and its Conversion to an Aluminum Tellurocarbonate by CO2 Reduction.

Facile access to dimeric heavier aluminum chalcogenides [(NHC)Al(Tipp)-μ-Ch]2 (NHC=IiPr (1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene, IMe4 (1,3,4,5-tetramethylimidazol-2-ylidene); Tipp=2,4,6-iPr3 C6 H2 ; Ch=Se, Te) by treatment of NHC-stabilized aluminum dihydrides with elemental Se and Te is reported. The higher affinity of IMe4 in comparison with IiPr toward the Al center in [(NHC)Al(Tipp)-μ-Ch]2 can be used for ligand exchange. Additionally, the presence of excess IMe4 allows for cleavage of the dimers to form a rare example of a neutral multiply bonded heavier aluminum chalcogenide in the form of a tetracoordinate aluminum complex, (IMe4 )2 (Tipp)Al=Te. This species reacts with three equivalents of CO2 across two Al-CNHC and the Al=Te bond affording a pentacoordinate aluminum complex containing a dianionic tellurocarbonate ligand [CO2 Te]2- , which is the first example of tellurium analogue of a carbonate [CO3 ]2- .

An Aluminum Telluride with a Terminal Al=Te Bond and its Conversion to an Aluminum Tellurocarbonate by CO2 Reduction

AbstractFacile access to dimeric heavier aluminum chalcogenides [(NHC)Al(Tipp)‐μ‐Ch]2 (NHC=IiPr (1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene, IMe4 (1,3,4,5‐tetramethylimidazol‐2‐ylidene); Tipp=2,4,6‐iPr3C6H2; Ch=Se, Te) by treatment of NHC‐stabilized aluminum dihydrides with elemental Se and Te is reported. The higher affinity of IMe4 in comparison with IiPr toward the Al center in [(NHC)Al(Tipp)‐μ‐Ch]2 can be used for ligand exchange. Additionally, the presence of excess IMe4 allows for cleavage of the dimers to form a rare example of a neutral multiply bonded heavier aluminum chalcogenide in the form of a tetracoordinate aluminum complex, (IMe4)2(Tipp)Al=Te. This species reacts with three equivalents of CO2 across two Al−CNHC and the Al=Te bond affording a pentacoordinate aluminum complex containing a dianionic tellurocarbonate ligand [CO2Te]2−, which is the first example of tellurium analogue of a carbonate [CO3]2−.

Impaired exercise capacity in individuals with non-obstructive small airway dysfunction.

Whether individuals with non-obstructive spirometry-defined small airway dysfunction (SAD) have impaired exercise capacity is unclear, particularly in never-smokers. This study clarifies the degree of impaired exercise capacity and its potential cause in individuals with non-obstructive SAD. This community-based, multiyear cross-sectional study analyzed data collected in Guangdong, China from 2012-2019 by the National Science and Technology Support Plan Program. Measurements of exercise capacity [peak work rate and peak oxygen uptake ( )] in participants with non-obstructive spirometry-defined SAD (n=157) were compared with those in controls (n=85) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) I patients (n=239). Subgroup analyses were performed by smoking status. The risk of impaired exercise capacity was significantly higher in participants with non-obstructive SAD [ <84%predicted, adjusted odds ratio (aOR) =2.53; 95% confidence interval (CI): 1.42-4.52] than in controls but was not significantly different from that in GOLD I patients. Results were consistent within subgroups of smoking status (ever-smokers: non-obstructive SAD vs. controls, aOR =2.44; 95% CI: 1.08-5.51; never-smokers: non-obstructive SAD vs. controls, aOR =2.38, 95% CI: 1.02-5.58). Participants with non-obstructive SAD had a significantly lower peak work rate (β=-10.5; 95% CI: -16.3 to -4.7) and (%predicted, β=-4.0; 95% CI: -7.7 to -0.2) and tended to have higher ventilatory equivalents for carbon dioxide at the ventilatory threshold ( , β=1.1; 95% CI: -0.1 to 2.3) when compared with controls. Both peak work rate and were negatively correlated with . Although not meeting the current criteria for chronic obstructive pulmonary disease, individuals with non-obstructive SAD have impaired exercise capacity that may be associated with ventilatory inefficiency regardless of smoking status.

The relationship between homocysteine and cardiopulmonary exercise testing in patients with acute coronary syndrome after percutaneous coronary intervention

ObjectiveThe purpose of this study was to investigate the relationship between homocysteine (Hcy) levels and cardiopulmonary exercise testing (CPET) in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). We also explored the relationship between Hcy levels and cardiac ultrasonography.MethodsThis study comprised 261 patients with ACS who underwent coronary angiography and PCI at Yulin First Hospital from January 2020 to June 2021. All subjects completed basic data collection, laboratory examination, CPET and cardiac ultrasonography. The CPET includes the peak oxygen uptake (peak VO2), anaerobic threshold (AT), metabolic equivalents (METs), exercise load (load), oxygen pulse (O2 pulse), end-tidal CO2 partial pressure (PETCO2), ventilatory equivalents for carbon dioxide (VE/VCO2) and Oxygen uptake efficiency (OUES). Cardiac ultrasonography was used to evaluate the left ventricular end diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT) and left ventricular ejection fraction (LVEF). A serum Hcy level ≥ 15 µmol/L was defined as hyperhomocysteinemia (HHcy). The patients were divided into the Hcy < 15 µmol/L group (n = 189) and the Hcy ≥ 15 µmol/L group (n = 72).ResultsThe average age of the participating patients was 58.9 ± 10.1 years. The majority of participants were male (86.6%). The CPET indices of METs, load, VO2/kg, and PETCO2 were significantly decreased in the Hcy ≥ 15 µmol/L group compared with the Hcy < 15 µmol/L group. Additionally, the CPET index of the VE/VCO2 slope and the cardiac ultrasonography indices of IVST and LVPWT were significantly increased in the Hcy ≥ 15 µmol/L group compared with the Hcy < 15 µmol/L group. These differences were statistically significant (P < 0.05). Correlation analysis showed that Hcy levels were negatively correlated with METs, VO2/kg and PETCO2 and positively correlated with the VE/VCO2 slope (P < 0.05). Partial correlation analysis showed that Hcy levels were negatively correlated with METs and VO2/kg in the AT state. The correlation coefficients were − 0.172 and − 0.172, respectively (P < 0.05). Hcy levels were negatively correlated with METs, VO2/kg and PETCO2 in the peak state. The correlation coefficients were − 0.177, -0.153 and − 0.129, respectively (P < 0.05). After further adjustment for confounders, multiple linear regression analysis showed that Hcy levels were negatively correlated with METs and VO2/kg in the AT state and peak state. The standardized regression coefficients were − 0.035, -0.122, -0.048 and − 0.128, respectively (P < 0.05). Correlation analysis showed that Hcy levels were positively correlated with the IVST and LVPWT (P < 0.05), but after adjusting for confounding factors, partial correlation analysis showed that there was no correlation between them.ConclusionA high Hcy level is associated with lower METs and VO2/kg and worse cardiopulmonary function in patients with ACS after PCI.

Possible Impact of Risk Management Strategies with Farm Model on a Mixed Farm Type

Abstract Background: Farm-level models have become an important tool for agricultural economists as there is a growing demand for microsimulation and analysis of farms at the individual level. Objectives: In this paper, we present a mathematical model with the main objective of assessing the effectiveness of production and various possible strategies for agricultural holdings by reducing risks. At the same time, we were also interested in the environmental impacts of such strategies. The latter was measured using the indicator of GHG emissions. Methods/Approach: The model applied is based on linear programming and upgraded with QRP for risk analysis. The approach was tested on medium size mixed agricultural holding, which often faces challenges in light of the structural changes taking place in Slovenia. Results: The results suggest that such a farm could improve financial results with a more efficient risk management strategy. With a slightly modified production plan, the expected gross margin (EGM) can be increased by up to 10% at more or less the same risk. However, if the farmer is willing to diversify the production plan and take a higher risk (+23%), the farm’s EGM could increase by up to 18%. This kind of change in the production plan would also generate 17% more GHG emissions in total, calculated as kg equivalent of CO2 at the farm level, as both BL and C scenarios have the same relative ratio at 3.12 GHG CO2 eq. /EUR. Conclusions: Through this research, we concluded that diversification has a positive potential on a mixed farm, and the farm could achieve better financial results. With flexibility in management, the farmer could also achieve higher risk management efficiency and better farm results.

Cardiorespiratory Parameters Do Not Account For Elevated Perceived Exertion In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Our prior meta-analysis of 37 case-control studies found that people with Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) perceive aerobic exercise as more effortful than otherwise healthy people (HP). Whether elevated perceived exertion (RPE) is disease specific or a secondary consequence of between-group differences in aerobic fitness or other cardiorespiratory parameters is not well studied. PURPOSE: Determine the influence of cardiorespiratory parameters on elevated RPE in people with ME/CFS. METHODS: We examined peak RPE responses during ramped cycle ergometry in 178 people with ME/CFS (age = 49.3 ± 13.2; BMI = 27.3 ± 6.9; % female = 65) and 169 HP (age = 42.5 ± 13.2; BMI = 26 ± 5.1; % female = 68). Subgroup analyses were conducted for 198 participants (99 ME/CFS; 99 HP) matched for age (±5 years) and peak oxygen consumption (VO2peak) (~1 ml/kg/min-1). Independent samples t-tests and Hedges’ d (d) effect sizes were used to test for between-group differences in RPE at peak exercise. A series of one-way analysis of covariance (ANCOVA) models with group (ME/CFS, HP) as the between-subjects factor tested whether peak cardiorespiratory parameters influenced between-group differences in RPE. These covariates included ventilatory equivalents for carbon dioxide and oxygen, heart rate, power, respiratory rate, and tidal volume. RESULTS: Mean ± SD peak RPE was 19.1(1) and 18.3(1.9) for ME/CFS and HP, respectively. Peak RPE was significantly higher in people with ME/CFS before (p < 0.001, d = 0.53; 95%CI: 0.32, 0.75) and after (p < 0.001, d = 0.56; 95%CI: 0.27, 0.84) matching for aerobic fitness. ANCOVA models revealed that between-group differences in RPE remained significant after including cardiorespiratory parameters as covariates in the model (all p < 0.05). CONCLUSIONS: People with ME/CFS perceive aerobic exercise as more effortful than HP, but these differences are not influenced by aerobic fitness or other cardiorespiratory factors. These findings extend those of our prior meta-analysis and also signify the importance of incorporating physiological measures beyond indirect calorimetry when studying mechanisms of elevated RPE in ME/CFS. Supported by Centers for Disease Control Contract AAD3581 to the University of Wisconsin-Madison.

Repeatability of ventilatory, metabolic and biomechanical responses to an intermittent incremental swimming protocol

Objective. This study aimed to determine the repeatability of ventilatory, metabolic and biomechanical variables assessed at a large spectrum of front crawl swimming intensities. We hypothesized a strong agreement (combined with a small range of variation) between a typical step protocol performed in two experimental moments. Approach. Forty competitive swimmers performed a 7 × 200 m front crawl intermittent incremental protocol (0.05 m·s−1 velocity rises and 30 s intervals) on two different occasions (48–72 h apart). Pulmonary gas exchange and ventilation were continuously measured breath-by-breath, metabolic variables were assessed during the intervals and biomechanical analysis was done at every protocol step. Main results. Concomitantly with the velocity increment, oxygen uptake, carbon dioxide production, ventilation, respiratory frequency, respiratory exchange ratio, averaged expiratory concentrations, end tidal oxygen and ventilatory equivalents for oxygen and carbon dioxide and blood lactate concentrations rose (p < 0.001), averaged expiratory concentrations and end tidal carbon dioxide and duration of inspiration, expiration and total breathing cycle decreased (p < 0.001), while tidal volume and volumes of oxygen and carbon dioxide expired maintained constant. Stroke frequency and stroke length increased and decreased (respectively) with the swimming velocity raise. No differences between experimental moments were observed in most of the assessed variables (p > 0.05), with a low dispersion (0.49%–9.94%) except for lactate concentrations and inspiration and expiration durations (11.00%–17.16%). Moderate-nearly perfect direct relationships and a good-excellent degree of reliability between moments were verified for all the assessed variables (r = 0.50–1.00, ICC = 0.76–1.00, p < 0.001), except for respiratory exchange ratio. Significance. The reliability analysis confirmed the repeatability of the assessed ventilatory, metabolic and biomechanical variables, with the obtained data well representing swimmers physiological condition when monitoring performance through a commonly used step protocol.